Dead Swans w H5N1 in west Asia and Europe

Hello together There seems to be another die off of Swans in Astrakhan and the neighboured kalmykian Republik. (The region is situated in the south west of Russia[

Area - 44.1 thousand square km, that is 0.3% of all territory of the Russian Federation. Length from west to east - 120 km, from north to south - 375 km. Climate is continental, dry. About 70% of the region`s territory is in zone of deserts. Relief is plain. http://www.regnum.ru/english/548230.html It remains unclear how far domestic poultry is involved. Has anybody further details? thanks

Swan infections indeed extraordinary.
Are these all mute swans, from Caspian Sea westward?

Though had whooper swan die in Mongolia last summer, no other wild swan deaths that I've noticed in east Asia.
Bewick's swans winter at Poyang, say, in some numbers (sorry, don't have figures; quick google reveals a bird tour counting over a thousand).
Were some bird deaths at Poyang around time Guan Yi et al obtained samples including from six ducks with H5N1 - but if lots of swan deaths, it has been kept quiet. If few or no swans died there, when sharing shallow lagoons [as reserve appeared to me my one visit - the huge lake shrinks in winter, only part is reserve] with infected ducks, surely more puzzling.
As I recall, black and black-necked swans have died of H5N1, in captivity in Hong Kong and neighbouring Shenzhen.

Qinghai indicates geese (well, bar-headed, tho again have been deaths in captivity) highly susceptible. Also graze in fields [as swans may do]

info from ornithologist Chris Feare:

[quote]Swans do indeed seem to be highly vulnerable and I cannot say why. They do
graze arable crops and grass, and they can forage on the bottom of water
bodies deeper than accessed by dabbling ducks. There may also be some
unknown physiological suscepribility - all speculation at this stage. Mute
swans forced to move by cold weather may be more susceptible to AI due to
stress/starvation. But cold weather might also force them to exploit unusual
food sources, possibly bringing them closer to infected material of some
sort.

We must, however, be clear about movements. The swans involved now are most
likely dispersing away from areas that are apparently experiencing extreme
cold in eastern Europe and western Asia. Mute Swans cannot feed on frozen
water bodies and so must move in search of open water. These birds have not
just arrived from Russia, but will have spent some weeks in areas that we
now know have infections in poultry. Furthermore, they are definitely not on
migration to Africa. Migrant mute swans occasionally reach Egypt and
possibly Algeria, but uncommon (Birds of Africa). Egypt does have some feral
mute swans, as does the Eastern Cape of South Africa. Whooper and Bewicks
swans both rarely visit N Africa. The current events, assuming they are
moving away from ice, do suggest that infected birds can travel a some
hundreds of km before dying, or that the infection is present over a wider
area than we thought and they pick it up on arrival at the new venue. The
implications of this are worrying.[/quote]

A dead Red-breasted Goose found on Skiros Island, Greece, has tested positive for H5N1. Another, found nearby, being tested. This is a beautiful goose species, regarded as globally Vulnerable to extinction

Three swans and a wild goose in Greece, up to 22 dead swans in southern
Italy and Sicily, and a swan in Slovenia have died of avian influenza.
Five of the Italian birds have tested positive for the deadly strain of
the H5N1 virus that originated in poultry and has been circulating
widely within Asia for the last decade. Bulgaria is expected to announce
its first cases of the virus soon in infected geese.

This is another worrying development in the spread of avian influenza
following the virus's appearance, last week, in Nigeria. Unlike the
African outbreak, however, which is restricted to poultry and was linked
by the government to the illegal import of infected chickens, the
European outbreaks involve wild birds.

All the swans are believed to be Mute Swans [i]Cygnus olor[/i], a species that
visits southern Italy and Greece from the Black Sea region. Their
movement into southern Europe is likely to be in response to freezing
weather conditions around the Black Sea.

In outbreaks of H5N1 so far, wild birds normally die within a few days
of infection. The appearance of the swans in Italy, Slovenia and Greece
indicates they were likely infected just prior to setting off on their
journeys.

It is possible the swans caught the disease from other wild birds,
although this is unlikely given the tens of thousands of waterfowl that
have tested negative for H5N1 over the last decade. A more likely route
is through contact with infected poultry or their faeces. Mute Swans,
like wild geese but unlike most ducks, often feed by grazing on
agricultural fields.
The practice of spreading poultry manure onto
fields as fertiliser is widespread in many parts of Eastern Europe, and
this is a possible source of infection. The United Nations Food and
Agriculture Organisation (FAO) has warned "Viruses can stay alive in the
manure for many weeks. If the manure is spread too quickly in the
fields, the virus may contaminate poultry." The swan deaths highlight
the need for implementation of strict biosecurity measures in infected
areas, and also highlight the need for monitoring of healthy wild birds
for the presence of the virus.

Swans seem particularly susceptible to H5N1 avian influenza, and Mute
Swan deaths have previously been reported in Russia and in October 2005
in Croatia. Tests on the Croatian swans found the birds excreted tiny
amounts of the virus. Even so, it was remarkable that waterbirds sharing
the same fish ponds as infected swans remained free of the disease.

The finding of dead swans will fuel the debate over how H5N1 is
spreading. However, if wild birds had been spreading the disease across
continents there would have been trails of dead birds following
migration routes, which isn't the case.

The "wild bird" theory for the
spread of H5N1 provides no explanation as to why certain countries on
flight paths of birds from Asia remain flu-free, whilst their neighbours
suffer repeated infections, nor of why only a single strain of H5N1 is
found in outbreaks west of China.

It seems to me that dead swans are now our harbinger of H5N1 transport.

They have been found in: Turkey, Iran, Azerbaijan, Greece, Italy, Slovenia, and Austria. Probably in more countries also. These I just listed are the countries affected in just the last two weeks that I can recall without doing more research.

How is it that swans can get around with the H5 virus? Do they possibly have a more robust immune system that lets them range afar before succumbing to the disease?

Or, is it a possibility that they are picking up the virus from an asymptomatic vector after arrival at their destination of demise?

I don't believe there was already H5N1 in all the places dead swans with H5N1 found (seems there have been movements spurred by freezing weather).

Yet, puzzling re just how and where they are being/have been infected.
(Earlier, had swans arrive Hungary in autumn, evidently healthy; move to Romania, and infected and dying - but H5N1 not found on ponds where they were dying.)

Are swans in east Asia, too; not many mute swans tho (the species impacted w Asia/Europe I believe). Not south to HK, but are in Japan westwards.
Yet, no problems evident w swans here, not even back to 2003/04.
Get various birds die from H5N1 - herons, egrets, gulls etc etc (even if you consider ducks somehow immune [by no means certain], or so few die that won't be evident).
Why, then, (mute) swans in Europe/w Asia?

Just seen reports re panicked people not feeding mute swans in Austria, Poland

Prompted me to send this missive around:

Wonder if people stopping feeding swans will have helped prompt them to move - especially in freezing weather - and with mute swans mainly sedentary in Europe (?), perhaps they were pretty clueless about where to go, so dispersed widely towards west and south. [While the affected whooper and Bewick's swans are in more regular places.]
Doesn't explain how and where they got infected.

In east Asia - China at least - swans not normally fed; indeed, can become food for people. Whether this is of some importance in swans in east Asia not being affected to marked extent (only 1 wild swan death reported?), hard to say.

Seen notions from Germany that the virus may have been present for months, only causing effects when temps very low. I'm sceptical about this.
In Hong Kong/Shenzhen - which get chilly but not below freezing - ornamental black and black-necked swans have died of H5N1. Yes, maybe these are more readily cold stressed than European swans (?), but died during outbreaks not cold spells.

Virus has now arrived in various places in Europe, in swans.
But, now to see whether it stays there - or will it die with the swans? (Romanian research important here I think: waterbirds sharing ponds with infected swans weren't infected; swans excreting only low amounts of virus. Hope more research like this is being done.)

Here in Hong Kong, no reports of H5N1 infected birds since the small flurry around Chinese New Year.
And, at apparent epicentre of H5N1 of Guangdong goose 96 lineage, no reports or sign of H5N1 in migratory waterbirds this autumn/winter. (All those who believe wild birds readily carry H5N1 - explain this please.)

-they don't have a regular dispersal from NE Greece, but in v cold snaps seem to head SW into Balkans and beyond, e.g. southern Italy where there have been previous cold weather influxes (remember the three that got as far as Malta then were shot a few years ago)

-a potentially significant difference to my mind between Whoopers and Mutes is that the Mutes tend to roost and feed in same place, up-end in deep water, whereas Whoopers in SE Europe and ?elsewhere tend roost on water, flight out to feed on cereal fields (for example, I've seen small numbers of Whoopers roosting with Mutes on Evros and then flighting inland at dawn whilst the Mutes stay put)

-similarly, the geese in Bulgaria tend to feed on autumn-drilled cereal where they can (i.e. with any spread manure etc. ploughed in some months before they arrive)

As a separate point, die-off of 135 "wild swans" reported on Iranian Caspian shore this week in the FT.

Just seen on birdforum - link to tv news video from German island with dying swans (on footage):
very sad
forum message says: "This is only hundreds of metres away from the Federal Animal Disease Research laboratory." (as another post mentions, how about chances of that?)

I've seen previously posted information about (mis)use of locally generated polutry manure at fishfarms, but quite an interesting post on UKBN today from Serbia, referring to extensive imports from China of poultry-based fertilizer to be used in fishponds. Exact constituents and usage not clear from post, but I assume this means fertilizer to be dumped into water to promote growth of weed/algae.

Includes mention re contaminated feed being thought to be a source of H5N1.
"The global trade in poultry feed, another factor in this whole mess, is dominated by the same companies. One of the standard ingredients in industrial chicken feed, and most industrial animal feed, is "poultry litter". This is a euphemism for whatever is found on the floor of the factory farms: fecal matter, feathers, bedding, etc.[43] Chicken meat, under the label "animal by-product meal", also goes into industrial chicken feed.[44] The WHO says that bird flu can survive in bird faeces for up to 35 days and, in a recent update to its bird flu fact sheet, it mentions feed as a possible medium for the spread of bird flu between farms.[45] [b]Russian authorities pointed to feed as one of the main suspected sources of an H5N1 outbreak at a large-scale factory farm in Kurgan province, where 460,000 birds were killed.[/b]"

So, got me wondering: is it possible that in areas where swans evidently dispersed from, they could have eaten contaminated feed?
Not sure if maybe poultry feed dumped as suspect (what happened to rest of the feed in Kurgan province, after problems surfaced, say?); or are there refuges where birds are fed in winter, as in some UK reserves?

Might help explain preponderance of mute swans, if directly fed (for some infections at least).

How the bird flu came to Germany, is further completely unclear.
While politicians and veterinarians before the beginning of the bird
course warn, experts refer to the gaps of the realizations: It seems,
as if could not have been wild geese, swans and ducks it alone.

The map of the world became a patch carpet. From China and Viet Nam
broad itself red fields out: Those countries, in which the bird flu
virus H5N1 breaks out. Countries seem almost daily to be added,
recently ever more European. And also when regarding the Germany map
the patch carpet association forces itself upon. It met ruegen as the
first, in the midst of H5N1-freier of neighboring countries. The
brandenburgischen districts concerned do not border evenly on the
island. East Holstein lies 150 kilometers further west. In order to
arrive at the Bodensee beach of Ueberlingen or the Mannheimer Rhine
bank, must the exciter the entire Federal Republic have diagonally
crossed. Has? Would have? Only how? Flown?

"it is missed to make migratory birds responsible for the bird flu",
said the Executive Secretary of the UN convention about moving animal
species (CMS), Robert Hepworth. For the spreading of the virus by
migratory birds give it no scientific vouchers.

Migratory birds under general suspicion

Ministers and veterinarians warn unisono of the beginning of the bird
course in approaching spring. Migratory birds are firstbest
suspecting. "if game birds the main carriers would be, for example
between China and Nigeria, then one would nevertheless expect, says
outbreaks on the distance between them also" Lenten. The dangerous
virus spread from the east to the west, the relevant bird course
routes run in north south direction. In the case ruegen it is added
that many swans concerned were at all no classical migratory birds,
but at best so-called Kaeltefluechter.

"I think nothing at all from this theory", say the micro biologist
Alexander Kekule of the University of resound Wittenberg. Because
after everything which one knows, works the virus in swans very fast
and very strongly. "Kekule fall in few days dead over", stress.
"one-way street thinking" calls the ornithologist Klaus Dieter fig
the thesis that game birds brought the virus in made of Eastern
Europe, where their breeding districts with those overlap themselves
to Asia of pulling birds. Cowardly one is a national boss of the
Ornithologi working group Mecklenburg-Western Pomerania.

Thomas Mettenleiter, boss of the Friedrich Loeffler institute speaks
only of the fact that "puzzlesteine" point on it who can itself have
moved exciters "stafettenartig" in the federal territory. In Lettland
of beringter Singschwan is considered as a main suspect: It was one
of the first animals, with which on ruegen H5N1 one determined.
During its takeoff it is to have been still healthy. "it was beringt
in Lettland, but we do not know, where it was infected, says" UN game
bird advocate Lenten. Officially the Osteekueste of Russia is
considered until to Usedom as H5N1-frei. Also cases of suspicion were
so far not announced.

Fear forwards and aggression against game birds

But how otherwise the exciter - in living birds, their meat or their
excrement - could have come to Central Europe? Bert Lenten enumerates
possibilities: Trade, smuggling, illegal Einfurh of living person or
totem poultry. "in Eastern Europe even the muck from chicken houses
is taken as fodder for fischteiche", said it. "we have the case of a
swan, that with its Beringung in Hungary were core healthy and two
days later dead in Croatia were gathered." Who only concentrates on
migratory birds as a carrier of H5N1, ignore other infection ways -
that is dangerous.

In January the Politpopulist Vladimir Schirinowski in the Russian
parliament had demanded to shoot all migratory birds with the return
from their Turkish winter districts. "the government must put a latch
plate for the bird course forward", demanded it. In Turkey in January
four children had died after a H5N1-Infektion. "the birds are to
remain, where they are", said the politician.

After I sent email to conservationists interested in H5N1, suggesting the virus apparently now scarcer in wild birds in Europe, as if self-limiting there too, seen this reply from an ornithologist working on H5N1:

My view of European (and Middle East and now Kazakhstan) outbreaks in wild birds is
(a) the spread did not follow a migration route,
(b) it did not occur at migration time,
(c) the ring recovery on Ruegen island indicated that the whooper swan contracted the virus on Ruegen: this indicates that the virus had been brought there, most likely (in the absecne of poultry infections) through leap-frog infections of birds that died after passing the infection to others,
(d) the movement of birds seems to have been stimulated by adverse weather, driving birds out of the Black Sea area where widespread and persistent infections in poultry had been present all winter.
This argument suggests that the virus remains lethal, and that infected
birds can't carry it vary far.

[quote]this indicates that the virus had been brought there, most likely (in the absecne of poultry infections) through leap-frog infections of birds that died after passing the infection to others[/quote]

Writing as a non-expert in disease, but as one who is really trying to understand the nature of H5N1, I would genuinely appreciate further advice and insight.

From what I understand, based on what we can be pieced together in East Asia, there has been no evidence at all for leap-frog infections between wild birds in this region.

Wild birds have come into contact with the virus: if they were infected, they died (in >99 % of known cases; and even in the v. significantly less than 1% remainder, we perhaps dont know whether death would have followed over time). In many cases (Qinghai, Mongolian lakes, Hong Kong), even birds sharing the same wetland with infected individuals did not become infected.

In the absence of an alternative hypothesis, is it not reasonable to assume that high path H5N1 (in East Asia at least) is very virulent, but that it is actually quite poor in terms of transmissibility? Is this not why it requires the dense concentrations of other birds in artificially maintained conditions to stay virulent and to transmit easily?

There have been, in over 9 years, no obvious or proven leap-frog infections between wild birds in Hong Kong, Japan, Korea, Mongolia and China, as far as can be made out.

Instead, it appeears wild birds were infected by more or less direct contact with infected poultry, poultry products/environmental contamination, caged birds, and in a few cases, where surely no other reasonable hypothesis exits, by scavenging on waste/dead birds (e.g. Magpie in Korea, Large-billed Crows in Japan). In all cases, the vast majority of wild birds remained uninfected. Consider those Magpies and Large-billed Crows (species that very often form large roosts in Korea and Japan): no large roosts were affected, and concentrated testing of these species in those countries showed no evidence of H5N1 in any but the birds that died.

If there had been wild bird to wild bird transmission, it would seem very likely that we would have seen ripples of spread, simultaneous outbreaks, sudden die-offs in wild bird flocks, LOTS more birds testing H5N1 positive in these countries. We have not. Instead, we have seen wild birds infected, and local deaths over a rather short time-frame (in all cases until Mongolia fairly easily explained by the local influence of poultry and poultry products or of market birds; and even in that case a gap of only a few hundred km from the infected poultry of southern Siberia, within the flight range of one or more likely several sick infected duck it seems, this in itself relevant to the European cases perhaps?).

What we have been seeing in Europe does seem to be different, at least on the surface. No mass die offs (in western europe at least), but instead scattered cases of deaths in a few species, from Tufted Ducks, especially Mute Swans over several weeks to e.g. a presumably scavenging Buzzard.

Looking closer, though it starts to look less different - East Asia minus the big die-offs...a few birds here, there, and in the absence of the local reservoir of the disease, or of more birds coming from an infected area, the so-called outbreaks seem to trail off.

There are several things that strike me as potentially significant in the Euopean pattern so far..would others agree? (asked without irony and in the hope of hearing peoples thoughts):

1) We know that infections in poultry have become endemic/near-endemic in parts of Turkey and elsewhere in SE/E Europe/W. Asia, and that the virus has become widespread in poultry in parts of Russia (pres all linked by a transport system);
2) We know that there has been a repeated state of denial about such outbreaks, and that trade through the region and from the region is very complex;
3) We know/suspect that there have been/were repeated outbreaks in wild birds in some of the same areas (ie parts of SE/E Europe/W. Asia), some outbreaks claimed to be large, then denied etc;
4) We know that there has been very severe and prolonged cold weather to the east of western europe, affecting some of the same regions;
5) we can see that the majority of infected wild birds are/were being found towards the east of Europe - Sweden, Germany, Italy etc, with none so far (is this correct) in the far west (i.e. UK, Spain , Portugal): ie in areas closest geographically to regions where the disease is already in poultry;
6) We know that bird movements and migration is far more complex than most people are presenting, with lots of smaller movements taking place and species-specific routes within flyways, which themselves are very wide at points (narrower at others). These more local movements include some species of geese and swans in mid-winter, with birds move west to eg the Netherlands, and then on to the UK only when conditions demand it, with in some winters birds even proven to commute between the two, responding to food availability and their fitness;
7) We can suspect that while some species were moving west from frozen wetlands into western Europe until very recently, that now some other species are moving north (I can see on UK birding websites news of the first Barn Swallows and Wheatears arriving, late but now in), as temperatures start to rise.
8) After a week or two of dead wild bird discoveries and new countries infected in western europe, it seems, for now, like the pace has changed - and infections are now being found again more often closer to the regional reservoir (eg outbreaks in Israel, human death in Egypt, continuing a fairly consistent spread closer to the epicentre)?
9) We can now see, for now at least, that the dead wild birds in (northern) parts of Europe were the last link in the chain of infection. They failed to infect other wild birds leap-frog style, unless perhaps through other species scavenging on them also becoming infected (again suggesting high virulence, poor rates of transmission?)
10) Finally, we do not know, but we can suspect, that there are now several potential sources of infection either within or just outside western Europe which can complicate the pattern further.

For the virus to leap frog between wild bird species, as a way of explaining scattered dead wild birds in Europe, would this not mean that the virus would need to have acquired a new level of transmissibility (so that it retains its high path state after repeated transmission in wild birds)?

If this is so, and in the absence of such a pattern In Asia, would not something likely have needed to change in the virus itself within recent weeks (this is asked without irony - I would very much like to understand)? Is there evidence of this?

And if so, if the virus has changed in this way, why are people in western Europe only apparently still only seeing the end link in that chain? Why, when these Mute Swans and Tufted Ducks reach western Europe and die, are there not continuing rippling patterns of spread on neighboring ponds and waterways?

Sent info from France, re the two largest wetlands in France evidently free of H5N1.
altavista babelfish translation of first article:

[quote]The two inspection networks of the birds of the regional park of the Camargue, the National office of hunting and wild fauna and the Tower of Valat, were shown reassured Monday as for the risk to discover an aviary case of influenza on their territory, one learned to the director from the park. According to Didier Olivery, on 1.500 birds analyzed to date, 5% presented cases of influenza but none was carrying virus H5N1.

"It is rather reassuring", declared Mr. Olivery, at the end of a meeting of the two networks which regularly take stock on the situation in the Camargue. "the Camargue was identified as the site more at the risk of France because a million migratory birds forward there, but one notes the opposite", declared Mr. Olivery.

The director of the park explains this report by two factors: "There is no site of intensive poultry breeding on the 100.000 hectares of the park, which in addition counts a very low density of population". A new peak of migration from Africa is waited until mid-April, "but not ducks", one of the principal reserves of virus H5N1, specified Mr. Olivery, adding that the park continued to reinforce its inspection network."[/quote]

Article on BBC site looks at the Curious Case of the Scottish Swan with H5N1.
Includes:
According to bird migration experts, the bird may not be native, and is a mute swan from the Baltic region or Black Sea that journeyed to the UK to escape a cold snap.

"This swan could have been part of a hard weather movement," Grahame Madge, from the RSPB, told the BBC News website.

"This is where you get hard weather in the Balkans or the Black Sea and water freezes over, meaning birds that need access to fresh water need to move - sometimes a few miles, sometimes 100 miles."

Mr Madge believed that a hard weather movement could have been responsible for the spread of H5N1 to France and Germany confirmed in February.

"The possibility is that this swan could have been part of the tail end of this movement, and might not have been a British-born bird at all."

Martin Fowlie from the British Trust for Ornithology (BTO) also suggested that this might be the case, and also raised the possibility that the swan may not have even died in the UK.

Eleven days after a swan with the bird flu virus was found in a seaside village, scientists still do not know what species it is, they said last night. Officials suggested last week that it was a resident mute swan, but DNA tests are being carried out to provide a positive identification. As a native bird it could only have caught flu from another bird flying to Britain, possibly a summer migrant arriving in the past few weeks. In that situation, the H5N1 virus that has killed more than 100 people worldwide could have been spreading through Britain's bird populations for some time. If the tests reveal that the carcass is that of a migratory species, such as a whooper swan, Britain could still escape a serious outbreak.
An infected migrant could have died while flying across the North Sea, before being washed ashore. Mark Avery, the director of conservation for the RSPB, said it was "pathetic" that scientists had not yet identified the headless carcass, recovered from the harbour in Cellardyke, Fife, on March 30. He added: "Whenever you have a case like this you need to know the species so you can better understand how the virus got here, how it has been transmitted and what the consequences are. It ought to be standard practice whenever there is a bird brought in with a suspicion of bird flu." A Defra spokesman said it was difficult to identify the headless bird, but it appeared to have the characteristics of a mute swan. She added that DNA tests at the Central Science Laboratory in York could be completed today.

turns out the Scottish swan was a whooper swan; ie a migratory species, wintering in UK and continental Europe.
More potential, then, for it to have been a migrant from continent, not even dying in UK.